Its unique design, featuring the filter cup and funnel fit offers flexibility to filter water into bottles with a wide range of mouth sizes, including narrow-mouth bottles such as commercial water bottles, soft drink bottles, canteens, and SIGG bottles. Compatible with Quantum Rapid Purification System Reservoir and other wider-mouth bottles, such as Klean Kanteen, Gatorade and Nalgene bottles, only the cup is necessary. Signal wordFitsAll, SteriPEN Article number: FAF-ADP SPECIFICATIONS Dimensions (in)- 0 x 0 x 0 Weight (oz)- 2 QUICK FACTS For solo use For more frequent use